Pulis, who took over in December 2017, led Boro to the play-off semi-finals last season but lost to Aston Villa.

Missing out on promotion will have a knock-on effect on Middlesbrough’s finances for 2019-20.

This season marked the end of their two-year run of parachute payments from the Premier League, following relegation in 2016-17.

Gibson said: “I’d like to thank Tony for his hard work and commitment over the past 18 months. He has been a joy to work with and a complete gentleman.

“Two years ago we invested heavily in the squad in terms of transfer fees and salaries in an attempt to regain our Premier League status. This happened before Tony’s arrival.

“Over the past 18 months Tony has been proactive, not only in the ambition to win football matches and promotion to the Premier League, but also in addressing our financial position in order to comply and respect the Championship fair play criteria.

“He has ensured that the club is stable and strong for the future. He leaves us in excellent condition.”

Boro fans disillusioned with style

Jordan Hugill scored six goals in 37 games for a stuttering Boro attack

The former Stoke City, Crystal Palace and West Brom boss’ initial appointment at the Riverside was greeted with optimism, thanks to his success in guiding the Potters into the Premier League and establishing them there.

However, his early success masked a disillusionment from sections of the support not wholly convinced by his tactics.

Boro had an enviable defensive record, conceding a joint-best low of 41 goals, but it was in attack that their promotion bid was hampered with just 49 goals – the lowest of any top-half side.

The pressure to reduce outgoings was eminent last summer, as the sale of star winger Adama Traore, forward Patrick Bamford and defender Ben Gibson pointed to a need to reduce the wage bill.

Although some money was reinvested in players, such as midfielder George Saville from Millwall and Bristol City defender Aden Flint, Pulis was largely forced to look to the loan market for additions.

There were highlights, such as free transfer Jon Mikel Obi and on-loan Everton midfielder Muhamed Besic, as well as the progress of young players such as Dael Fry and Lewis Wing.

However, others such as boyhood Boro fan Jordan Hugill – loaned from West Ham – were unable to supply the firepower needed.

Analysis

Paul Addison, sports editor at BBC Tees

Tony Pulis was a very divisive figure from his very first day as the Middlesbrough manager.

His functional style of play frustrated many fans, but they saw their side reach the play-offs in the 2017-18 season before surrendering to Aston Villa in the semi-finals.

Boro were in the top six for most of the 2018-19 campaign but a run of six successive defeats ultimately did for their promotion hopes and, in the end, for Pulis.

The atmosphere at home games became toxic on occasions when supporters voiced their displeasure by labelling Pulis’ style as “Jurassic”.

The manager insisted throughout his time at the Riverside that he had helped to “balance the books” and clear up some of the damage that he said had been done by his predecessor Garry Monk in terms of big money transfers and high wages.

Pulis told BBC Tees Sport after the final game against Rotherham United that finishing seventh was in many ways a bigger achievement than reaching the play-offs in the previous season – that, for many, was the last straw.